Community water security - UN-Water

Water for Life
15
Toxic chemicals in water
Factories that produce food products, textiles, plastics, pharmaceuticals, cosmetics,
and pesticides all release chemical waste into water sources. This makes
the water unsafe to drink or to use for bathing
or irrigation. These chemicals are usually
invisible and very difficult to detect.
Toxic chemicals can enter the water in many ways.
The only way to know what chemicals are in the water is to test it at a laboratory. And
the only way to ensure that water is free of toxic chemicals is to prevent chemical
contamination at the source. To prevent contamination from toxic chemicals:
• Factories should take responsibility for treating their wastes.
• Industries like mining and oil drilling should not be done in places where water
is at risk.
• Governments should set standards to prevent industrial pollution of water
sources and ensure that these standards are enforced.
• Farmers who use pesticides and fertilizers should use them in limited amounts
and ensure that these chemicals do not enter water sources.
Arsenic in Bangladesh
Some toxic chemicals exist naturally in the earth. When these chemicals enter our
drinking water they can be deadly. This is very rare, but as water becomes scarce the
risk of natural toxins grows.
The worst case of water poisoning from naturally occurring toxic chemicals was
in Bangladesh in 1983. Many people started getting very ill with problems like skin
lesions, cancer, nerve damage, heart disease and diabetes, and many were dying. It was
one of the largest public health disasters the world had ever seen — and no one knew
what was causing it.
In 1993, scientists learned that the cause of the illnesses was arsenic, a toxic
chemical that was in the drinking water. Many years before, the government and
international agencies had built thousands of tubewells in Bangladesh to provide safe
drinking water. Before the arsenic poisoning, most people drank surface water, often
contaminated with germs that led to death from diarrhea and other diseases. When the
tubewells were built, nobody knew that water should be tested for arsenic.
Today there are many programs in Bangladesh to prevent poisoning by providing
special water filters and new arsenic free water sources. But what could have been
done to prevent the poisoning in the first place? The mystery is still not solved. Was the
poisoning of so many people accidentally caused by a development project intended
to save lives? The answer is not simple. The only way to prevent poisoning from toxic
chemicals is to know what is in the water naturally, and to prevent any activity that
may poison the water.
See page 47, Where to get more information, for a low cost method to remove
arsenic from water.